Hundreds of thousands of patients each year suffer from infections after surgery, and experts say more than half of those infections stem from bacteria the patients themselves are carrying in their nose or on their skin. Otherwise harmless bacteria can enter the body through surgical incisions and cause infections that can require expensive treatment, slow recovery or even cause death.

But two new studies suggest relatively simple ways hospitals can prevent many infections by killing the bacteria on the patient before surgery, with methods of screening, scrubbing or pretreating the patient that many hospitals do not typically use.

“This is going to be a huge help to the infection-control crowd,” said Marcia Patrick, a nurse and board member of the Association for Professionals in Infection Control and Epidemiology, who was not involved with either study. “How can we not do this? It would truly be penny-wise and pound-foolish. And it’s the right thing to do for patients.”

The studies, published Thursday in The New England Journal of Medicine, examined infections that develop at the site of surgery, often around the incision, and afflict more than 300,000 patients a year in the United States.